Synthesis and Consolidation of Nano-Sized NiCo Powder by Powder Technology Rout

Abstract

Nano sized Co-20wt%Ni composite powder was synthesized by electroless chemical reduction method using metallic salt precursors and hypophosphite as a reducing agent in alkaline tartarate bath as a complexing agent. The synthesized powder provide better sinterability, mechanical, electrical and magnetic properties with homogeneous microstructure. The nano-sized powder could be obtained, which have the average particle size of 40 nm, with a saturation magnetization (Bs ) of 97.95 which was increased by heat treatments of powder in hydrogen to 127 emu/g due to the exclusion of the precipitated phosphrous in the composite powder. The powder underwent cold compaction at 600 Mpa and sintering at 1050 oC for 30 min. The saturation induction for the sintered material of 149.3 emu/g higher than the synthesized powder and has electrical resistivity value of 7.6 μcm.